Selectively illuminated push buttons for radio receiver tuners



J. L. WHITTAKER 2,532,212 SELECTIVELY ILLUMINATED PUSHBUTTONS FOR RADIO RECEIVER TUNERS 2 Sheets-Sheet 1 Nov. 28, 1950 Filed Jan. 30, 1946 I N V EN TOR. c/amev L wl zyier BY 41 AYTOJPA/H.

Patented Nov. 28, 1950 SELECTIVELY ILLUMINATED PUSH BUT- TONS FOR RADIO RECEIVER TUNERS James L. Whittaker, Princeton, N. J assignor to Radio Corporation of America, a corporation of Delaware Application January 30, 1946, Serial No. 644,200

Claims.

This invention relates generally to dial operators and indicators and more particularly to selectively illuminated push-button elements for actuating contact mechanisms of radio receiver tuners or the like.

In conventional pushebutton motor tuners for radio receivers, a plurality of separate push-buttons are provided for actuating individual contact units for tuning the radio receiver to each of a plurality of radio frequency channels. -Heretofore push-buttons of this type have been of plastics or other opaque material, and illLunina-ted station escutcheons have been located adjacent to each of the push-buttons to indicate the respective tuning channels. The only manner in which the operator could determine the channel or station tuning of the receiver has been to note which of the push buttons is depressed or actuated. Observation of push-buttonactuation is extremely diflicult if the operator chances to be located at some distance from the apparatus.

The instant invention contemplates a pushbutton system including means for illuminating distinctively the actuated one of a plurality of push-buttons, for indicating from a distance which of the push-buttons is in an operative position. The invention may be incorporated in any existing push-button actuator mechanisms with but slight change in the structure thereof. The invention contemplates the use of clear plastic push-buttons shaped in any desired manner as heretofore. Those of the push-buttons which are not actuated or depressed are shielded from an adjacent light source by means of a suitably shaped light mask. The light source may comprise a conventional dial lamp which also is employed for illuminating the manual tuning dial. However, when one of the pushbuttons is depressed by the operator, the inner end of the push button extends beyond the mask, and that particular push-button is illuminated by the dial lamp, thereby clearly indicating from a distance which one of the plurality of pushbuttons has been actuated.

The station escutcheons located adjacent to the push-buttons may be illuminated continuously by the same light source as is employed for selectively illuminating the push buttons, or a separate source may be utilized. If desired, the

individual push-buttons may include a translucent outer portion containing station identification data, in which case the separate escutcheons may be illuminated. The push-button actuator system, disclosed herein by way of illustration, comprises two groups of four. push-buttons each of which actuate separate station tune ing contact units, and a spring operated contact interlock mechanism which locks the actuated push-button and contact unit in an operable condition and automatically unlocks any previously actuated push-button and contact units. A tie bar interconnecting the locking mechanisms of the two groups of push-buttons permits the interlocking feature to be operable simultaneously upon both groups.

Among the objects of the invention are to provide an improved method of and means for illuminating push-button actuators. Another object is to provide an improved push-button actuator which is selectively illuminated when in an operable position. A further object is to provide a plurality of push-button, contact units which are selectively interlocked and in which the push-buttons are selectively illuminated from a common light source only upon actuation thereof. An additional object is to provide an improved push-button tuning mechanism for radio receivers, or the like, wherein selective actuation of each of the push-buttons provides selective illumination thereof thereby permitting distant observation of the operation of the system.

The invention will be described in great-er de tall by reference to the accompanying drawing of which Figure 1 is an elevational view of a conventional radio receiver dial mechanism including the invention, Figure 2 is a partially cross-sectional plan view of said dial mechanism showing the structure of'a preferred type of push-button actuator in accordance with the invention, and Figure 3 is a fragmentary crosssectional plan View of an alternative type of push-button actuator in accordance with the invention. Similar reference characters are applied to similar elements throughout the drawing.

Referring to Figures 1 and 2 of the drawing, a conventional multiband radio receiver dial mechanism includes a manual tuning dial I with separate frequency scales 3, 5, 1 for a plurality of tuning bands. A common dial indicator 9 is operable with all three frequency band scales, and the selected tuning band is indicated by selective illumination of the tuning band indicia H, l3, I5. In addition two groups [1, l9, each of four push-buttons 2!, 23, 25, 21, each including four sets of tuning contact units 29, are disposed on opposite sides of the manual tuning dial. Each of the contact units is connected to the motor control or station selection circuits, as the case may be, so that upon actuation of the particular contact unit, a predetermined tuning frequency is automatically selected. The details of the electrical connections to the contact units are omitted, since they may .be varied in accordance with-known technique and are not essential to an understanding of the invention.

The several contact units 29 each include a movable contact 3| having a shoulder portion 33 which may be locked by a pivoted catch 35, so that, when the contacts are depressed by the operation of the separate push-buttons 2|, 23, 25, 21, the catch locks under the-shoulder of the actuated movable contact unit and automatilustratedin an operative position, and the'push- I button 23 being shown in an inoperative position. The push-buttons each comprise a clear plastic element having .a shoulder 39 which engages a stop ll forming a portion of the pushbutton guide to prevent the push-button from a traveling beyond a predetermined distance from the front of the panel. Also a recessed shoulder 43 is provided on the inner side of the push button to-engage with a second stop for preventing excessive depression .of the push-button i when it is actuated. The inner end 4! of the push button 2i engages the front surface of the movable contact 6i which includes the shoulder contact portion-33. Thus actuation of the push-button releases the pivoted catch 35, thereby releasing any previously-actuated pushbuttons and contacts, and then the catch locks under the last actuated push-button shoulder and retains it in operative position.

A light source, such as a dial lamp49, located behind the manual tuning dial l, provides illumination for each group of push-buttons. If desired, -a separate light source may be provided for each push-button contact group and the .light sources ma-y be employed for separate or common illumination of the manual tunin and push-button tuning mechanisms. A fixed mask 5| located between the push-button light source 49 and each group of push buttons prevents illumination of any of the push-buttons unless one of them is depressed to actuate a particular contact unit. When the push-button is depressed to actuate its associated contact unit, the inner end 47 of the push-button extends beyond the shadow of the mask 5! and is illuminated by the light source. Preferably the inner end 47 of the push-button should have a roughened surface which, when illuminated by the light source, provides, by internal reflection within the plastic push-button, illumination of the outer end 53 of the push-button which may be observed at a considerable distance by the operator.

Due to normal light reflections from the associated push-button contacts, very slight illumination of all push-buttons will occur at all times, thereby permitting easy operation of the pushbuttons in a completely darkened room. However, when a particular push-button is actuated, the intensity of illumination observable at the outer end 53 thereof is readily distinguishable from the faint illumination of all of the other inoperative push-buttons. It should be understood that, if desired, the contact units and other adjacent apparatus may be blackened to minimize the residual illumination of the pushbuttons in their inoperative positions.

Figure 3 shows a modified form of clear plastic push-button comprisin a mushroom-shaped clear plastic unit 55, which is journaled in the receiver front panel '51 and is held in position by the inherent spring tension of the associated contact units -29. The shoulder 41 of the pushbutton 55 preferably is roughened to provide better illumination contrast and greater light efficienc when the push-button is actuated.

Thus the invention disclosed comprises a relatively simple modification of conventional push-button actuators which, while entailing but slight additionalexpense over conventional units, provides selective illumination of each :of-aplurality of push-button actuators substantially only upon actuation thereof.

I claim as my invention:

1. In a control system, a plurality of transparent pushbuttons each-having a shankportion and an enlarged shoulder portion providing a stop and a light gathering medium, a panel having apertures therethrough for said sharikportions of said pushbuttons, a source of light adjacent to the back of said panel and said pushbuttons, and means fixedly disposed between said source and said pushbuttons for selectively illuminating said shoulder portions of said pushbuttons by said source to provide a distinctive source of illumination at the ends of said shank portions of said pushbuttons at the front of said panel substantially only when said pushbuttons are actuated.

2. In a control system, a plurality of transparent pushbuttons "each'havin a shank .portion and an enlarged shoulder portion providing 'a stop and a light gathering medium, a panel having apertures therethrough for said shank portions of said pushbuttons, a source of lightadjacent to the back of said panel and said pushbuttons, and a mask fixedly disposed between said source and said pushbuttons, said mask being proportioned so that said shoulder portions of said pushbuttons are selectively 'illuminatedby said source and provide a distinctive source of illumination at the ends of said shank portions of said pushbuttons at the front of said panel substantially only when said pushbuttons are actuated.

3. In a control system, a plurality of transparent pushbuttons each having a shank portion and an enlarged shoulder'portion providing a stop and a light gathering medium, a panel having apertures therethrough for said shank portions of said pushbuttons, a source of light adjacent to the back of said panel and arranged to selectively illuminate substantially only said shoulder portions of a plurality of said pushbuttons, and a mask fixedly disposed between said source and said pushbuttons, said mask being proportioned so that said shoulder portions of said pushbuttons are selectively illuminated by said source and provide a distinctive source of illumination at the ends of said shank portions of said pushbuttons at the front of said panel substantially only when said pushbuttons are depressed.

4. In a control system, a plurality of transparent pushbuttons each having a shankportion and an enlarged shoulder portion, '"a panel having apertures therethrough for said shank portions of said pushbuttons, a source of light adjacent to the back of said panel and said shoulder portions of said pushbuttons, and a mask fixedly disposed between said source and said pushbuttons, said mask being proportioned so that said shoulder portions of said pushbuttons are selectively illuminated by said source and provide a distinctive source of illumination at the end of said pushbutton shank at the front of said panel substantially only when said pushbuttons are depressed.

5. In a control system, a plurality of transparent pushbuttons each having a shank portion and an enlarged shoulder portion providing a stop and a light gathering medium, a reduced shoulder portion on said shank portion providing a second stop, a panel having apertures therethrough for said shank portions of said pushbuttons, a stop device for selectively engaging with said second stop of each of said pushbuttons, a source of light adjacent to the back of said panel and said pushbuttons, and a plurality of masks each supported by one of said stop devices and fixedly disposed between said source and said pushbuttons, said masks being proportioned so that said enlarged shoulder portions of said pushbuttons are selectively illuminated by said source and provide a distinctive source of illumination at the ends of said shank portions of said pushbuttons at the front of said panel substantially only when said pushbuttons are actuated.

JAMES L. WHITTAKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

